1. Technical Field
The present invention pertains to temperature sensing and monitoring systems. In particular, the present invention pertains to systems for measuring and displaying the temperature of intravenously delivered fluids and other medical items.
2. Discussion of Relevant Art
Intravenously delivered fluids and other medical items are generally required to have temperatures within specific temperature ranges in order to avoid serious injury to a patient. Although there exist warming systems to heat items to their corresponding temperature ranges, medical personnel generally do not have a manner in which to ascertain temperature of the items once the items have been removed from those systems. In addition, medical personnel generally do not have a manner in which to ascertain fluid temperature during infusion into a patient. The relevant art has attempted to overcome these problems by providing a manner in which to measure and indicate temperature of fluids prior to delivery to a patient. For example, U.S. Pat. No. 522,866 (Weinhagen et al), U.S. Pat. No. 803,352 (Meyer) and U.S. Pat. No. 2,204,764 (Mayo) disclose containers having thermometers attached thereto for indicating the temperature of fluid residing in the containers. The containers are constructed to enable the thermometer bulb to access the fluid for temperature measurement.
U.S. Pat. No. 3,864,976 (Parker) discloses a laminated digital thermometer secured to a container, such as a wine bottle or a baby bottle, for determining the temperature of a fluid contained therein. The thermometer is in the form of a digital thermometer strip providing a specific digital temperature indication of fluid within the container.
U.S. Pat. No. 4,859,360 (Suzuki et al) discloses a blood bag having a temperature-monitoring device in the form of a tag or label adhered to the bag outer surface. The temperature-monitoring device includes plural reversible temperature indicators each associated with a specific temperature range to indicate a current temperature of the blood, and an irreversible temperature indicator to indicate that the blood has currently or previously reached a predetermined temperature. The reversible indicators individually provide visual indications in response to the current blood temperature being within a corresponding range, while the irreversible indicator maintains a visual indication once the predetermined temperature has been reached.
With respect to ascertaining fluid temperature during infusion, U.S. Pat. No. 3,651,695 (Brown) discloses a temperature indicator for fluid conduits that changes color in response to temperature. A color reference chart is provided adjacent the indicator to indicate the temperatures corresponding to the color variations.
U.S. Pat. No. 5,806,528 (Magliochetti) discloses an irrigation fluid delivery system including a fluid delivery tube having a temperature sensing device for measuring and providing a visual indication of the fluid temperature prior to delivery to a patient. The temperature sensing device is disposed in the tube in stripe form and typically exhibits at least one color change in response to a change in temperature to indicate fluid temperature.
The relevant art suffers from several disadvantages. In particular, the Weinhagen et al, Meyer and Mayo devices require special attachment mechanisms to affix thermometers to containers, while the containers are configured to provide the thermometers with access to the fluid, thereby increasing complexity and cost of these systems. Further, in the case of medical or sterile fluids, these systems enhance the possibility of fluid contamination, thereby risking injury to a patient. Moreover, since the thermometers tend to be rigid and fragile, the thermometers may be easily damaged during transport and/or storage of the containers. In addition, thermometer temperature indications tend to be difficult to read, thereby requiring additional time and complicating ascertainment of the fluid temperature.
Although the Parker and Suzuki et al temperature devices are less intrusive and display a specific digital temperature indication of a fluid, these devices operate within a narrow temperature range. Thus, the Parker and Suzuki et al temperature devices are limited in application to fluids having acceptable temperatures within a specific and narrow temperature range. If a fluid temperature extends beyond that narrow range, these devices do not provide a manner in which to indicate that temperature.
The Brown and Magliochetti systems do not provide a specific temperature indication. Rather, these systems employ color indications requiring users to reference or recollect the temperature color scheme, thereby requiring additional time and complicating ascertainment of fluid temperature.
Accordingly, it is an object of the present invention to measure and numerically indicate a temperature of intravenously delivered fluids via a temperature sensing strip prior to delivery to a patient.
It is another object of the present invention to measure and numerically indicate a temperature of intravenously delivered fluids residing within containers (e.g., bags, bottles, etc.) via a temperature sensing strip attached to and in thermal relation with the container.
Yet another object of the present invention is to measure and numerically indicate a temperature of intravenous fluids during infusion to a patient via a temperature sensing strip attached to and in thermal relation with a fluid delivery tube.
Still another object of the present invention is to measure and visually indicate temperature of medical containers via a stand, plate, receptacle or other structure employing a temperature sensing strip.
A further object of the present invention is to measure and visually indicate temperature of medial items within a thermal treatment system via temperature sensitive strips residing within thermal treatment system compartments.
The aforesaid objects are achieved individually and/or in combination, and it is not intended that the present invention be construed as requiring two or more of the objects to be combined unless expressly required by the claims attached hereto.
According to the present invention, an intravenous solution bag includes a temperature sensing device in the form of a temperature sensing strip. The strip includes a temperature scale and corresponding temperature sensitive substances that change color or illuminate the scale indicators to visually indicate solution temperature. The strip may be formed integral with the bag, may be attached to the bag exterior surface, may be laminated to the bag exterior surface or may be encased with the bag within a solution bag liner. Further, the temperature sensing strip may be affixed to bottles containing intravenous or other solutions, where the strip is attached to the bottle exterior surface or to a label affixed to the bottle to measure and indicate temperature of fluid contained therein as described above. Moreover, the temperature sensing strip may be employed by an infusion apparatus to measure and indicate solution temperature prior to or during infusion. In this case, the strip may be affixed to a receptacle suspending a solution bag, or to a fluid delivery tube to measure and indicate temperature as described above. In addition, the temperature sensing strip may be disposed within thermal treatment system compartments to measure and provide a visual indication of temperatures of medical items residing within the compartments.
Alternatively, the strip may be employed by a stand, plate, receptacle or other structure receiving a medical item or container. The item is placed in the structure in thermal relation with the strip to facilitate a temperature measurement and indication as described above. The structure may be a stand-alone unit or may be attached to a thermal treatment or other system to facilitate temperature measurement.
The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of specific embodiments thereof, particularly when taken in conjunction with the accompanying drawings wherein like reference numerals in the various figures are utilized to designate like components.